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BACKGROUND: Little information is available regarding the precise swine leukocyte antigen (SLA)-derived immunogenic peptides that are presented in the context of human HLA molecules. Here, we identified SLA-derived immunogenic peptides that are presented in association with human HLA-A2 molecule. METHODS: The SLA-derived peptides that bind to HLA-A*0201, a representative of the A2 supertype, were predicted using a computer-assisted algorithm. The candidate peptides were synthesized, and the stabilities of complexes formed between peptides and HLA-A*0201 were compared using major histocompatibility complex (MHC) stabilization assays. The cytotoxic T lymphocyte (CTL)-inducing activity of the selected peptides was examined in HLA-A*0201-transgenic mice. RESULTS: Among 15 candidate peptides synthesized, two peptides, peptide-35 (YLGPDGLLL) and peptide-43 (TLICHVDSI), were selected to have high affinity and stability with HLA-A*0201. Examination of the CTL-inducing activity of the two peptides in HLA-A*0201-transgenic mice showed that immunization with peptide-35, but not peptide-43, elicited potent CD8-specific CTL responses. The Peptide-35 is present in non-polymorphic α2 domains of 34 SLA-1 alleles, 18 SLA-2 alleles, and 1 SLA-3 allele. CONCLUSION: This study identifies an immunogenic HLA-A*0201-restricted epitope derived from the SLA, which may be valuable for the development of epitope-specific immunoregulation strategies.
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Epitopos de Linfócito T/imunologia , Antígeno HLA-A2/imunologia , Antígenos de Histocompatibilidade Classe II/imunologia , Animais , Antígenos de Histocompatibilidade Classe I , Humanos , Ativação Linfocitária/imunologia , Camundongos , Camundongos Transgênicos , Suínos , Transplante HeterólogoRESUMO
The influenza virus poses a global health burden. Currently, an annual vaccine is used to reduce influenza virus-associated morbidity and mortality. Most influenza vaccines have been developed to elicit neutralizing Abs against influenza virus. These Abs primarily target immunodominant epitopes derived from hemagglutinin (HA) or neuraminidase (NA) of the influenza virus incorporated in vaccines. However, HA and NA are highly variable proteins that are prone to antigenic changes, which can reduce vaccine efficacy. Therefore, it is essential to develop universal vaccines that target immunodominant epitopes derived from conserved regions of the influenza virus, enabling cross-protection among different virus variants. The internal proteins of the influenza virus serve as ideal targets for universal vaccines. These internal proteins are presented by MHC class I molecules on Ag-presenting cells, such as dendritic cells, and recognized by CD8 T cells, which elicit CD8 T cell responses, reducing the likelihood of disease and influenza viral spread by inducing virus-infected cell apoptosis. In this review, we highlight the importance of CD8 T cell-mediated immunity against influenza viruses and that of viral epitopes for developing CD8 T cell-based influenza vaccines.
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The fate of developing T cells is determined by the strength of T cell receptor (TCR) signal they receive in the thymus. This process is finely regulated through the tuning of positive and negative regulators in thymocytes. The Family with sequence similarity 49 member B (Fam49b) protein is a newly discovered negative regulator of TCR signaling that has been shown to suppress Rac-1 activity in vitro in cultured T cell lines. However, the contribution of Fam49b to the thymic development of T cells is unknown. To investigate this important issue, we generated a novel mouse line deficient in Fam49b (Fam49b-KO). We observed that Fam49b-KO double positive (DP) thymocytes underwent excessive negative selection, whereas the positive selection stage was unaffected. Fam49b deficiency impaired the survival of single positive thymocytes and peripheral T cells. This altered development process resulted in significant reductions in CD4 and CD8 single-positive thymocytes as well as peripheral T cells. Interestingly, a large proportion of the TCRγδ+ and CD8αα+TCRαß+ gut intraepithelial T lymphocytes were absent in Fam49b-KO mice. Our results demonstrate that Fam49b dampens thymocytes TCR signaling in order to escape negative selection during development, uncovering the function of Fam49b as a critical regulator of the selection process to ensure normal thymocyte development and peripheral T cells survival.
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Receptores de Antígenos de Linfócitos T , Transdução de Sinais , Timócitos , Animais , Camundongos , Sobrevivência Celular , Camundongos Knockout , Receptores de Antígenos de Linfócitos T/metabolismo , Receptores de Antígenos de Linfócitos T/genética , Linfócitos T/imunologia , Timócitos/metabolismo , Timócitos/citologiaRESUMO
Duodenal mucosal resurfacing (DMR) by thermal ablation of the duodenal mucosa is a minimally invasive endoscopic procedure for controlling metabolic syndrome (MS). However, thermal energy can cause adverse effects due to deep mucosal injury, necessitating an additional mucosal lifting process, which complicate the procedures. Therefore, we aimed to develop a similar procedure using non-thermal photodynamic therapy (PDT) for DMR using a highly functional metal stent covered with photosensitizers (PSs) to minimize the potential risks of thermal ablation injury. We developed a novel PS stent enabling the controlled release of radical oxygen species with specific structures to prevent stent migration and duodenal stricture after ablation and performed an animal study (n = 8) to demonstrate the feasibility and safety of PDT for DMR. The stents were placed for 7 days to prevent duodenal strictures after PDT. To confirm PDT efficacy, we stained for gastric inhibitory polypeptide (GIP) and glucose transporter isoform 1. The PS stents were deployed, and PDT was applied without evidence of duodenal stricture, pancreatitis, or hemorrhage in any of the pigs. Microscopic evaluation indicated apoptosis of the mucosal cells in the irradiated duodenum on days 7 and 14, which recovered after day 28. Immunohistochemistry revealed suppressed GIP expression in the mucosal wall of the irradiated duodenum. Endoscopic PDT for DMR using PS stents could be applied safely in a porcine model and may result in decreased GIP secretion, which is a crucial mechanism in MS treatment. Further clinical studies are required to explore its safety and efficacy in patients with MS.
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Regulatory T cells (Treg) are crucial immune modulators, yet the exact mechanism of thymic Treg development remains controversial. Here, we present the first direct evidence for H2-O, an MHC class II peptide editing molecular chaperon, on selection of thymic Tregs. We provide evidence that lack of H2-O in the thymic medulla promotes thymic Treg development and leads to an increased peripheral Treg frequency. Single-cell RNA-sequencing (scRNA-seq) analysis of splenic CD4 T cells revealed not only of an enrichment of effector-like Tregs but also of activated CD4 T cells in the absence of H2-O. Our data support two concepts; a) lack of H2-O expression in the thymic medulla creates an environment permissive to Treg development and, b) that loss of H2-O drives increased basal auto-stimulation of CD4 T cells. These findings can help in better understanding of predispositions to autoimmunity and design of therapeutics for treatment of autoimmune diseases.
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Regulatory T cells (Treg) are crucial immune modulators, yet the exact mechanism of thymic Treg development remains controversial. Here, we present the first direct evidence for H2-O, an MHC class II peptide editing molecular chaperon, on selection of thymic Tregs. We identified that lack of H2-O in the thymic medulla promotes thymic Treg development and leads to an increased peripheral Treg frequency. Single-cell RNA-sequencing (scRNA-seq) analysis of splenic CD4 T cells revealed not only an enrichment of effector-like Tregs, but also activated CD4 T cells in the absence of H2-O. Our data support two concepts; a) lack of H2-O expression in the thymic medulla creates an environment permissive to Treg development and, b) that loss of H2-O drives increased basal auto-stimulation of CD4 T cells. These findings can help in better understanding of predispositions to autoimmunity and design of therapeutics for treatment of autoimmune diseases.
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Doenças Autoimunes , Linfócitos T CD4-Positivos , Humanos , Ativação Linfocitária/genética , Linfócitos T Reguladores , Antígenos de Histocompatibilidade Classe II , Diferenciação CelularRESUMO
The endoplasmic reticulum aminopeptidase associated with antigen processing (ERAAP) plays a crucial role in shaping the peptide-major histocompatibility complex (MHC) class I repertoire and maintaining immune surveillance. While murine cytomegalovirus (MCMV) has multiple strategies for manipulating the antigen processing pathway to evade immune responses, the host has also developed ways to counter viral immune evasion. In this study, we find that MCMV modulates ERAAP and induces an interferon γ (IFN-γ)-producing CD8+ T cell effector response that targets uninfected ERAAP-deficient cells. We observe that ERAAP downregulation during infection leads to the presentation of the self-peptide FL9 on non-classical Qa-1b, thereby eliciting Qa-1b-restricted QFL T cells to proliferate in the liver and spleen of infected mice. QFL T cells upregulate effector markers upon MCMV infection and are sufficient to reduce viral load after transfer to immunodeficient mice. Our study highlights the consequences of ERAAP dysfunction during viral infection and provides potential targets for anti-viral therapies.
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Apresentação de Antígeno , Muromegalovirus , Animais , Camundongos , Aminopeptidases/metabolismo , Linfócitos T CD8-Positivos , Retículo Endoplasmático/metabolismo , Antígenos de Histocompatibilidade Classe I/metabolismo , Leucil Aminopeptidase/metabolismo , Peptídeos/metabolismoRESUMO
Objective: Early chemoresistance and tumor mass progression are associated with poor prognosis in pancreatic ductal adenocarcinoma (PDAC). Circulating tumor cells (CTCs) have been studied as potential predictors of treatment response and prognosis in PDAC; however, this approach has yet to be applied in clinical practice. The aim of our study was to investigate the phenotypic characteristics of CTCs and determine their predictive value for PDAC progression. Methods: We prospectively enrolled 40 patients who were pathologically diagnosed with PDAC and collected blood samples at diagnosis, 2 months after diagnosis, and during disease progression or recurrence. We used a microfabricated filter-based enrichment system to retrieve and analyze CTCs, which were classified using immunofluorescence staining (CD45, EpCAM, and vimentin). Results: Our study included 20 women and 20 men (median age, 66 years). Overall, 45% of the patients (18/40) had disseminated disease, and 77.5% (31/40) received chemotherapy. Multivariate analysis revealed that the total CTC count and carbohydrate antigen 19-9 level at 2 months after diagnosis were associated with disease progression (P<0.05). Linear mixed model analysis revealed that the total CTC count and vimentin-positive CTCs were significantly correlated with treatment response during chemotherapy (P=0.024 and 0.017, respectively). Kaplan-Meier analysis showed that total CTC positivity at 2 months was significantly associated with poor progression-free survival (P=0.038). Conclusion: Our study's findings suggest that CTCs can serve as predictive biomarkers of clinical outcomes in patients with PDAC receiving palliative chemotherapy. In particular, the total CTC count and vimentin-positive CTCs showed changes associated with the chemotherapy response.
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Indirect recognition of xenoantigens has been implicated as the major mechanism underlying xenospecific CD4+ T-cell activation in chronic rejection. We identified swine leukocyte antigen (SLA)-derived immunogenic peptides that are presented in the context of human HLA-DR4 molecules. The SLA class I-derived peptides that bind HLA-DRB1*0401, a representative of the DR4 supertype, were predicted using a computer-assisted algorithm. The candidate peptides were synthesized, and their binding capacities to HLA-DRB1*0401 were compared in a competitive ELISA using biotinylated hemagglutinin reporter peptides [HA(307-319)]. Peptide-11 (LRSWTAADTAAQISK) was determined to exhibit the most potent binding capacity to HLA-DRB1*0401 in vitro and thus selected for in vivo immunization. Immunization of HLA-DRB1*0401-transgenic mice with peptide-11 elicited potent CD4+ Th1 responses. Peptide-11 shares homology to α2 domains of three SLA-1 alleles, six SLA-2 alleles, and 14 SLA-3 alleles. Thus, this study has important implications not only for the identification of an immunogenic indirect epitope shared by diverse SLA class I alleles, but also for the development of epitope-specific immunoregulation strategies.
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Antígenos Heterófilos/imunologia , Antígeno HLA-DR4/imunologia , Antígenos de Histocompatibilidade Classe II/imunologia , Sequência de Aminoácidos , Animais , Anticorpos Heterófilos/biossíntese , Antígenos Heterófilos/genética , Epitopos de Linfócito T/genética , Antígeno HLA-DR4/genética , Antígenos de Histocompatibilidade Classe I , Antígenos de Histocompatibilidade Classe II/genética , Humanos , Ativação Linfocitária , Camundongos , Camundongos Transgênicos , Dados de Sequência Molecular , Fragmentos de Peptídeos/genética , Fragmentos de Peptídeos/imunologia , Sus scrofa/genética , Sus scrofa/imunologia , Linfócitos T/imunologia , Transplante HeterólogoRESUMO
Chronic inflammation plays a critical role in the development of obesity-associated metabolic disorders such as insulin resistance. Obesity alters the microenvironment of adipose tissue and the intestines from anti-inflammatory to pro-inflammatory, which promotes low grade systemic inflammation and insulin resistance in obese mice. Various T cell subsets either help maintain metabolic homeostasis in healthy states or contribute to obesity-associated metabolic syndromes. In this review, we will discuss the T cell subsets that reside in adipose tissue and intestines and their role in the development of obesity-induced systemic inflammation.
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Vaccination with tumor peptide epitopes associated with MHC class I molecules is an attractive approach directed at inducing tumor-specific CTLs. However, challenges remain in improving the therapeutic efficacy of peptide epitope vaccines, including the low immunogenicity of peptide epitopes and insufficient stimulation of innate immune components in vivo. To overcome this, we aimed to develop and test an innovative strategy that elicits potent CTL responses against tumor epitopes. The essential feature of this strategy is vaccination using tumor epitope-loaded nanoparticles (NPs) in combination with polyinosinic-polycytidylic acid (poly-IC) and anti-PD1 mAb. Carboxylated NPs were prepared using poly(lactic-co-glycolic acid) and poly(ethylene/maleic anhydride), covalently conjugated with anti-H-2Kb mAbs, and then attached to H-2Kb molecules isolated from the tumor mass (H-2b). Native peptides associated with the H-2Kb molecules of H-2Kb-attached NPs were exchanged with tumor peptide epitopes. Tumor peptide epitope-loaded NPs efficiently induced tumor-specific CTLs when used to immunize tumor-bearing mice as well as normal mice. This activity of the NPs significantly was increased when co-administered with poly-IC. Accordingly, the NPs exerted significant anti-tumor effects in mice implanted with EG7-OVA thymoma or B16-F10 melanoma, and the anti-tumor activity of the NPs was significantly increased when applied in combination with poly-IC. The most potent anti-tumor activity was observed when the NPs were co-administered with both poly-IC and anti-PD1 mAb. Immunization with tumor epitope-loaded NPs in combination with poly-IC and anti-PD1 mAb in tumor-bearing mice can be a powerful means to induce tumor-specific CTLs with therapeutic anti-tumor activity.
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Some BTC types respond to pembrolizumab, but there are no known prognostic factors to predict its treatment benefits. In this study, we attempted to identify the prognostic factors associated with pembrolizumab as a second-line treatment for gemcitabine-refractory BTC. This retrospective and single tertiary-center study involved all the consecutive patients (n = 80) with refractory advanced BTC, who were diagnosed as programmed cell death ligand 1-positive and treated with pembrolizumab between August 2017 and February 2021. The overall survival (OS) was analyzed using Cox regression analysis. The median OS was 6.0 months [95% confidence interval (CI): 3.87−8.20]; median progression-free survival was 1.9 months (95% CI: 1.82−1.98); and the response rate was 15.9%. In the multivariate Cox regression analysis, the TB [adjusted hazard ratio (HR) = 2.286; 95% CI: 1.177−4.440; p = 0.015), albumin levels (adjusted HR = 0.392; 95% CI: 0.211−0.725; p = 0.003), ALP levels (adjusted HR = 1.938; 95% CI: 1.105−3.400; p = 0.021), and LMR (adjusted HR = 0.325; 95% CI: 0.173−0.609; p < 0.001) were identified as significant variables associated with the OS. High albumin levels and LMR and low ALP levels and TB were significantly associated with better OS in patients treated with pembrolizumab.
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Tumor peptides associated with MHC class I molecules or their synthetic variants have attracted great attention for their potential use as vaccines to induce tumor-specific CTLs. However, the outcome of clinical trials of peptide-based tumor vaccines has been disappointing. There are various reasons for this lack of success, such as difficulties in delivering the peptides specifically to professional Ag-presenting cells, short peptide half-life in vivo, and limited peptide immunogenicity. We report here a novel peptide vaccination strategy that efficiently induces peptide-specific CTLs. Nanoparticles (NPs) were fabricated from a biodegradable polymer, poly(D,L-lactic-co-glycolic acid), attached to H-2Kb molecules, and then the natural peptide epitopes associated with the H-2Kb molecules were exchanged with a model tumor peptide, SIINFEKL (OVA257-268). These NPs were efficiently phagocytosed by immature dendritic cells (DCs), inducing DC maturation and activation. In addition, the DCs that phagocytosed SIINFEKL-pulsed NPs potently activated SIINFEKL-H-2Kb complex-specific CD8+ T cells via cross-presentation of SIINFEKL. In vivo studies showed that intravenous administration of SIINFEKL-pulsed NPs effectively generated SIINFEKL-specific CD8+ T cells in both normal and tumor-bearing mice. Furthermore, intravenous administration of SIINFEKL-pulsed NPs into EG7.OVA tumor-bearing mice almost completely inhibited the tumor growth. These results demonstrate that vaccination with polymeric NPs coated with tumor peptide-MHC-I complexes is a novel strategy for efficient induction of tumor-specific CTLs.
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Tetracyclines, which have long been used as broad-spectrum antibiotics, also exhibit a variety of nonantibiotic activities including anti-inflammatory and immunomodulatory properties. Tetracyclines bind to the 30S ribosome of the bacteria and inhibit protein synthesis. Unlike antimicrobial activity, the primary molecular target for the nonantibiotic activity of tetracycline remains to be clarified. Nonetheless, the therapeutic efficacies of tetracyclines, particularly minocycline and doxycycline, have been demonstrated in various animal models of autoimmune disorders, such as multiple sclerosis, rheumatoid arthritis, and asthma. In this study, we summarized the anti-inflammatory and immunomodulatory activities of tetracyclines, focusing on the mechanisms underlying these activities. In addition, we highlighted the on-going or completed clinical trials with reported outcomes.
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The active form of vitamin D3, 1,25-dihydroxyvitamin D3 (aVD3), is known to exert beneficial effects in the treatment of autoimmune diseases because of its immunosuppressive effects. However, clinical application of aVD3 remains limited because of the potential side effects, particularly hypercalcemia. Encapsulation of aVD3 within biodegradable nanoparticles (NPs) would enhance the delivery of aVD3 to antigen presenting cells, while preventing the potential systemic side effects of aVD3. In the present study, polymeric NPs containing ovalbumin (OVA) and aVD3 (NP[OVA+aVD3]) were prepared via the water-in-oil-in-water double emulsion solvent evaporation method, after which their immunomodulatory effects were examined. Bone marrow-derived immature dendritic cells (DCs) treated with NP(OVA+aVD3) did not mature into immunogenic DCs but were converted into tolerogenic DCs, which express low levels of co-stimulatory molecules and MHC class II molecules, produce lower levels of pro-inflammatory cytokines while increasing the production of IL-10 and TGF-ß, and induce the generation of Tregs. Intravenous injection with NP(OVA+aVD3) markedly suppressed the generation of OVA-specific CTLs in mice. Furthermore, OVA-specific immune tolerance was induced in mice orally administered with NP(OVA+aVD3). These results show that biodegradable NPs encapsulating both antigen and aVD3 can effectively induce antigen-specific immune suppression.
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PURPOSE: Dexamethasone (Dex) has long been used as a potent immunosuppressive agent in the treatment of inflammatory and autoimmune diseases, despite serious side effects. In the present study, Dex and model antigen ovalbumin (OVA) were encapsulated with poly(lactic-co-glycolic acid) to deliver Dex and OVA preferentially to phagocytic cells, reducing systemic side effects of Dex. The OVA-specific immune tolerance-inducing activity of the nanoparticles (NPs) was examined. METHODS: Polymeric NPs containing OVA and Dex (NP[OVA+Dex]) were prepared by the water-in-oil-in-water double emulsion solvent evaporation method. The effects of NP[OVA+Dex] on the maturation and function of immature dendritic cells (DCs) were examined in vitro. Furthermore, the OVA-specific immune tolerizing effects of NP[OVA+Dex] were confirmed in mice that were intravenously injected or orally fed with the NPs. RESULTS: Immature DCs treated in vitro with NP[OVA+Dex] did not mature into immunogenic DCs but instead were converted into tolerogenic DCs. Furthermore, profoundly suppressed generation of OVA-specific cytotoxic T cells and production of OVA-specific IgG were observed in mice injected with NP[OVA+Dex], whereas regulatory T cells were concomitantly increased. Feeding of mice with NP[OVA+Dex] also induced OVA-specific immune tolerance. CONCLUSION: The present study demonstrates that oral feeding as well as intravenous injection of poly(lactic-co-glycolic acid) NPs encapsulating both antigen and Dex is a useful means of inducing antigen-specific immune tolerance, which is crucial for the treatment of autoimmune diseases.
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Antígenos/imunologia , Materiais Biocompatíveis/química , Dexametasona/farmacologia , Epitopos/imunologia , Tolerância Imunológica , Nanopartículas/química , Administração Oral , Animais , Apresentação de Antígeno/efeitos dos fármacos , Citocinas/biossíntese , Células Dendríticas/efeitos dos fármacos , Células Dendríticas/imunologia , Feminino , Fatores de Transcrição Forkhead/metabolismo , Imunidade/efeitos dos fármacos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Nanopartículas/administração & dosagem , Ovalbumina/imunologia , Fagocitose/efeitos dos fármacos , Copolímero de Ácido Poliláctico e Ácido Poliglicólico/química , Linfócitos T Citotóxicos/imunologia , Linfócitos T Reguladores/efeitos dos fármacos , Linfócitos T Reguladores/metabolismoRESUMO
In the era of precision medicine, the prediction of ovarian function recovery from chemotherapy-induced amenorrhoea using feasible biological markers may be helpful to optimise the treatment strategy for young patients with hormone receptor-positive breast cancer. The purpose of this study was to investigate the accuracy of post-chemotherapy biological markers for predicting the recovery of ovarian function in breast cancer patients of the ASTRRA trial, with chemotherapy-induced amenorrhoea. Using data of 82 participants from a single institution in the ASTRRA trial, the post-chemotherapy serum levels of the anti-Müllerian hormone (AMH), oestradiol, inhibin B and other clinical factors associated with chemotherapy-induced amenorrhoea were evaluated. Recovery of ovarian function was defined by the resumption of menstruation manifested by vaginal bleeding. Fifty-two patients regained menstruation within 55 months after enrolment. In univariate analysis, <40 years of age (P = 0.009), oestradiol ≥37 pg/mL (P = 0.003) or AMH ≥800 pg/mL (P = 0.026) were associated with recovery of menstruation. On multivariate analysis, oestradiol (hazard ratio: 3.171, 95% CI: 1.3067.699, P = 0.011) and AMH (hazard ratio: 2.853, 95% CI: 1.0118.046, P = 0.048) remained as significant independent predictors for resumption of menstruation. The diagnostic accuracy of age, oestradiol and AMH in predicting the resumption of menstruation was 38.3, 23.3 and 86.7%, respectively. In conclusion, post-chemotherapy AMH level might be a relatively accurate predictor of the recovery of ovarian function, presented by resumption of menstruation in breast cancer patients with chemotherapy-induced amenorrhoea
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Tolerogenic dendritic cells (tDCs) represent a promising tool for cellular therapy against autoimmune diseases, allergies, and transplantation rejection. Numerous pharmacological agents are known to induce tDC generation. Minocycline, which has long been used as a broad-spectrum antibiotic, was recently shown to significantly increase the generation of DCs with regulatory properties. Here, we examined the effect of the combination of minocycline with dexamethasone, rapamycin, vitamin D3, and interleukin (IL)-10, which are all known inducers of tDC generation. The highest number of tDCs was generated when minocycline and dexamethasone were used together with granulocyte colony-stimulating factor (GM-SCF) and IL-4. The tolerogenicity of the minocycline/dexamethasone-conditioned tDCs was much better than or at least equal to those of the tDCs generated with either one of these agents, as assessed through in vitro phenotypic and functional assays. In addition, pretreatment with MOG35-55 peptide-pulsed minocycline/dexamethasone-conditioned tDCs significantly ameliorated the clinical signs of experimental autoimmune encephalitis induced by MOG peptide injection in a murine model. These results confirmed that tDCs with potent tolerogenic properties could be efficiently generated by the combined use of minocycline and dexamethasone, along with GM-CSF and IL-4. Our results would help in the development of ex vivo tDC-based immunotherapies.
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Células Dendríticas/efeitos dos fármacos , Dexametasona/farmacologia , Tolerância Imunológica/efeitos dos fármacos , Minociclina/farmacologia , Animais , Antibacterianos/farmacologia , Anti-Inflamatórios/farmacologia , Doenças Autoimunes/imunologia , Doenças Autoimunes/terapia , Células da Medula Óssea/efeitos dos fármacos , Diferenciação Celular/efeitos dos fármacos , Células Cultivadas , Células Dendríticas/imunologia , Feminino , Fator Estimulador de Colônias de Granulócitos e Macrófagos , Tolerância Imunológica/imunologia , Imunoterapia/métodos , Interleucina-4/farmacologia , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BLRESUMO
Minocycline, which has long been used as a broad-spectrum antibiotic, also exhibits non-antibiotic properties such as inhibition of inflammation and angiogenesis. In this study, we show that minocycline significantly enhances the generation of dendritic cells (DCs) from mouse bone marrow (BM) cells when used together with GM-CSF and IL-4. DCs generated from BM cells in the presence of minocycline (Mino-DCs) demonstrate the characteristics of regulatory DCs. Compared with control DCs, Mino-DCs are resistant to subsequent maturation stimuli, impaired in MHC class II-restricted exogenous Ag presentation, and show decreased cytokine secretion. Mino-DCs also show decreased ability to prime allogeneic-specific T cells, while increasing the expansion of CD4+CD25+Foxp3+ T regulatory cells both in vitro and in vivo. In addition, pretreatment with MOG35-55 peptide-pulsed Mino-DCs ameliorates clinical signs of experimental autoimmune encephalitis induced by MOG peptide injection. Our study identifies minocycline as a new pharmacological agent that could be potentially used to increase the production of regulatory DCs for cell therapy to treat autoimmune disorders, allergy, and transplant rejection.
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Apresentação de Antígeno/efeitos dos fármacos , Células da Medula Óssea/efeitos dos fármacos , Células Dendríticas/efeitos dos fármacos , Minociclina/farmacologia , Transferência Adotiva/métodos , Animais , Apresentação de Antígeno/imunologia , Células da Medula Óssea/imunologia , Proliferação de Células/efeitos dos fármacos , Células Cultivadas , Células Dendríticas/imunologia , Células Dendríticas/transplante , Encefalomielite Autoimune Experimental/imunologia , Encefalomielite Autoimune Experimental/terapia , Feminino , Teste de Cultura Mista de Linfócitos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Minociclina/imunologia , Glicoproteína Mielina-Oligodendrócito/imunologia , Fragmentos de Peptídeos/imunologia , Linfócitos T/efeitos dos fármacos , Linfócitos T/imunologia , Linfócitos T Reguladores/efeitos dos fármacos , Linfócitos T Reguladores/imunologiaRESUMO
The preventive effect of a processed Aloe vera gel (PAG) on colon carcinogenesis was examined using an azoxymethane (AOM)-initiated and dextran sodium sulfate (DSS)-promoted mouse colon carcinogenesis model. Oral administration of PAG (200, or 400mg/kg/day) significantly reduced the multiplicity of colonic adenomas and adenocarcinomas compared with the AOM/DSS only-treated mice. In the mice treated with 400mg/kg of PAG, adenoma and adenocarcinoma development was reduced to 80% and 60%, respectively, compared to 100% in the PAG-untreated AOM/DSS-treated mice. Western blot analysis using colon extracts showed that PAG reduced the activation of nuclear factor kappa B (NF-κB), resulting in the inhibition of inducible nitric oxide synthase and cyclooxygenase-2 expression. PAG appeared to inhibit the NF-κB activation through the activation of peroxisome proliferator-activated receptor gamma. PAG also inhibited the expression and phosphorylation of signal transducer and activator of transcription 3, which is known to connect inflammation and cancer. In addition, PAG inhibited cell cycle progression-inducing cellular factors, such as extracellular signal-regulated kinases 1/2, cyclin-dependent kinase 4, and cyclin D1. On the other hand, PAG increased the expression of Caudal-related homeobox transcription factor 2, which is known to be a tumor suppressor in colorectal cancer. These findings show that PAG suppresses colitis-related colon carcinogenesis by inhibiting both chronic inflammation and cell cycle progression in the colon.